1. Field of the Invention:
This invention relates to a video signal processing device, and, more particularly, to a video signal processing device highly suited for an apparatus arranged to process a video signal including line sequential signals which have an offset level, at least in part.
2. Description of the Related Art:
Generally, the process of rearranging line sequential signals into concurrent signals necessitates discrimination of the kind of the signals for every horizontal scanning period (hereinafter referred to as H period). Therefore, in recording or transmitting these signals, they are processed into some signal form that permits discrimination of their kinds. For example, in recording signals of two kinds by arranging them in a line sequential manner, the DC component (hereinafter referred to as DC) has an offset of a 2-H period.
In accordance with the conventional process for rearranging the DC offset line sequential signals of this kind into concurrent signals, the voltage of each H period is sampled and held during a portion of the H period within which the DC offset is detectable; and then the above-stated discrimination is accomplished by comparing the sampled voltage with a predetermined level. The line sequential signals are made concurrent on the basis of a discriminating signal thus obtained.
However, the conventional apparatus which is arranged to perform the above-stated process is required to detect the slight levels of the line sequential signals of two kinds and, accordingly, to have a circuit constant arranged to a high degree of precision. Besides, it is necessary also to adjust the circuit constant. Further, since a large number of capacitors must be used, the conventional arrangement has been not suited for integration of the circuit and thus hindered efforts to arrange the apparatus in a compact size.